Posting this thread as a result of questions in a different thread:
First, a wee bit of history (everyone's favorite subject - unless it might be math or physics
)
Through the 1925 model year, Chevrolet at various times used Carter, Detroit Lubricator (Stewart), Holley, Marvel, Stromberg, and Zenith carburetors.
By 1926, Chevrolet had settled on one manufacturer of carburetors - Carter
WHY?
Sometime in the early 1920's, Chevrolet wanted to build some of the carburetors themselves in their Bay City plant. Carter was the only carburetor manufacturer that would allow Chevrolet to do this.
The Chevrolet built carburetors are easily identifiable from their Carter cousins by the large letter "C" cast into the casting. Updraft carburetor had the "C" as a prefix to the carburetor type. As an example the most common of the Carter updrafts used by Chevrolet is the RJH-08 used in 1929 (136s) and 1930-31 (150s). These carburetors built in the Bay City plant would have the cast identification of C-RJH-08. And these carburetors were tagged with the identification number; however the original updraft tags were red cardboard, and few have survived. I have only seen one. And before someone corrects me that they have a RJH-08 with a 150s brass tag, please be advised the carbs were continued to be produced as "service replacement carbs" after the production year. Those produced in 1932 and later would have the brass tag. Those carburetors built by Carter would have the Carter part number; while those carburetors produced by Chevrolet would have the Chevrolet part number.
The W-1 carburetors had the large "C" separate from the type;
Bay City produced W-1Both the large "C" and the "W-1" are shown in the above picture.
Why is the above information important (to many, it may not be)
However, to those who are trying to restore a vehicle as correctly as possible, the Carter tag (example 574s) would be found only on castings WITHOUT the large "C"; whereas, the Chevrolet tag (using the same example 839987) would be found only on the castings with the large "C".
The Carter tags will have a 3 or 4 digit number, followed by the letter "S". In Carterspeak, there were parts, and there were assemblies. An idle mixture screw is a single part, thus a common idle mixture screw might be 30A-81 (no "S"); whereas a fuel valve (a.k.a. needle and seat) might be 25-33s. The fuel valve is an "assembly" of multiple parts - the seat, the valve, and the gasket. Most enthusiasts eliminate the "S" when referring to the carburetor identification number (computers do not like a letter in a numeric field); but the "S" would be on the tag.
The Carter tags in various years, might carry other information, such as:
Date code - in the format month year. Thus A7 would be produced in January of some year ending in 7 (maybe 1947). B=February, C=March, etc.
Individual quality control stamp - most common are an 8-pointed star, and a half moon.
Final inspection control stamp - generally a two digit number (the final inspector's number) stamped at a 45 degree angle to other information.
An engineering status stamp - if a modification significant enough that it warranted note, but not sufficiently significant to warrant a new ID number, the letter "S" would be appended to the "S". I cannot recall seeing one of these on a W-1, but trying to cover all bases.
I have fewer Chevrolet tags, but the ones I have indicate: the date code, the individual quality stamp, and the final quality stamp. However, the final quality stamp was a character (half moon etc.) rather than a number.
More information on Carter W-1's used on Chevrolet may be found here:
Article on Carter Chevrolet W-1 carburetorsI probably missed something in this post. If I did, feel free to ask. I am still trying to get out from under that "shade tree", and need more posts
Jon.
